1,721,113 research outputs found
Una strategia di prevenzione sismica a basso costo per edifici di culto e monumentali: presidi provvisori in fibre sintetiche o metalliche
No full textSi propone la strategia di adottare presidi provvisori preventivi, da mettere in opera all’insorgere di uno sciame sismico e rimuovere al termine del fenomeno, specifica per fabbricati di culto di valore storico artistico. Si utilizzano nastri in FRP o metallici per solidarizzare o confinare manufatti strutturali (colonne, pareti, tamburi, volte) con particolare riguardo ad edifici di culto o monumentali
Stress‒strain curves for masonry materials exposed to fire action
No full textOn the basis of the results obtained by an extended experimental campaign aimed to the mechanical characterization of main masonry materials subjected to fire action, the
variation factors of compression strength, ultimate strain in absence of preload and the apparent modulus of elasticity were detected in function of the temperature increasing.
The stress‒ strain readings permitted to define sets of couples of data on which an uniaxial constitutive law, in comparison to those proposed by European standards, is defined and subsequently validated for each tested material. The error indexes produced by the various constitutive models are also determined and compared. The out-of-plane mechanical behaviour of the horizontal cross sections of full units masonry panels is then investigated: the adopted method is able to define the axial force–bending moment crushing domains for increasing exposure time to nominal fire, considering different types of stress–strain–temperature constitutive relations
Simple Tests and Mechanical Model for Masonry Materials at High Temperatures
No full textAn experimental procedure for tests on specimens made of several materials is performed to detect the mechanical properties depending from temperature. About 200 cylindrical specimens of several materials (clay, lightweight concrete, aerate autoclaved concrete, mortar) are tested from 20°C to 700°C. The free thermal strain and the decay of axial strength are determined; proposals for the
stress-strain curves and the secant modulus of elasticity in function of temperature are illustrated. The data base from tests are able to calculate the collapse domains (bending moment - axial force - time of exposure to nominal fire) which represent a simple model for the assessment of masonry panel sections subjected to fire action
Application of RCW Base Dissipator on a Set of Masonry Buildings
No full textAn application of the RCW –Reinforced Cut Wall- on a set of four masonry buildings for council housing estate with a total of 43 lofts is presented. The performances of this low-cost base energy dissipation technique has been evaluated with some experimental on-site tests performed on a couple of specimen (40x60x30 cm) subjected to a series of cyclic quasi-static time histories with increasing intensity. Trials show the high properties of self-centering and of wide hysteretic behavior of the RCW. Numerical analyses confirm the mechanical properties and provide parameters to the evaluation of cyclic dissipation properties
Simple tests and mechanical model for masonry materials at high temperatures
No full textAn experimental procedure for tests on specimens made of several materials is performed to detect the mechanical properties depending from temperature. About 200 cylindrical specimens of several materials (clay, lightweight concrete, aerate autoclaved concrete, mortar) are tested from 20°C to 700°C. The free thermal strain and the decay of axial strength are determined; proposals for the stress-strain curves and the secant modulus of elasticity in function of temperature are illustrated.
The data base from tests are able to calculate the collapse domains (bending moment - axial force - time of exposure to nominal fire) which represent a simple model for the assessment of masonry panel sections subjected to fire action
Progettazione all'incendio delle strutture in muratura secondo EN 1996-1-2
No full textSi presenta una procedura analitica di verifica della capacità portante di murature in presenza di incendi
Application of RCW base dissipator on a set of masonry buildings
No full textAn application of the RCW –Reinforced Cut Wall- on a set of four masonry buildings for council housing estate with a total of 43 lofts is presented. The performances of this low-cost base energy dissipation technique has been evaluated with some experimental on-site tests performed on a couple of specimen (40x60x30 cm) subjected to a series of cyclic quasi-static time histories with increasing intensity. Trials show the high properties of self-centering and of wide hysteretic behavior of the RCW. Numerical analyses confirm the mechanical properties and provide parameters to the evaluation of cyclic dissipation propertie
Bamboo trusses with low cost and high ductility joints
No full textInnovative solutions of joints for bamboo trusses are presented. Experimental tests show the performances and the high level of ductility of the proposed technique, joined with simplicity in the concept of the joints, low level of technology and low cost of all used materials. It can permit a proper dissemination and a sustainable maintenance in developing countries
Behaviour of masonry walls subjected to fire: experimental tests and analytical model
No full textExperimental tests on blocks for masonry walls made by several materials are performed to detect the compressive strength depending from temperature: about 400 cylinders - diameter D=100 mm height H=200 mm - are tested from 20°C to 700°C of clay, lightweight concrete, aerate autoclaved concrete, calcium silicate. The data base from tests has been used to calculate the collapse domains (bending moment - axial force – time of exposure on fire). A numerical example shows the applicability of the proposed method
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